It is well known to provide a motorboat of the outboard type or of the inboard-outboard type with a trolling attachment which enables the spped of the boat to be reduced sufficiently for trolling purposes, so that a boat which would otherwise be too powerful to operate at trolling speeds can be converted for such use. Trolling attachments commonly take the form of flaps secured to the transom of a boat for lowering into the water so as to produce drag effective to reduce the speed of the boat.
The present invention seeks to provide an improved trolling attachment including a pivotal flap which can be raised and lowered manually or automatically, which can be secured to a boat transom with securing means above the waterline, to reduce the possibility of leaks, which can be adapted to outboard or inboard-outboard type boats, and which has means for adjusting the force required to move the flap between raised and lowered positions.